sms_ntsc_benchmark: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/sms_ntsc_benchmark - from package: sms_ntsc-demos

You may install the required package with command yum install {package}
Error in other languages:
sms_ntsc_benchmark: bevel nie gevind nie
sms_ntsc_benchmark: comandă negăsită
sms_ntsc_benchmark: comando não encontrado
sms_ntsc_benchmark: commande introuvable
sms_ntsc_benchmark: command not found
sms_ntsc_benchmark: käsku ei ole
sms_ntsc_benchmark: không tìm thấy lệnh
sms_ntsc_benchmark: komanda nerasta
sms_ntsc_benchmark: Kommando nicht gefunden.
sms_ntsc_benchmark: kommandot finns inte
sms_ntsc_benchmark: komut yok
sms_ntsc_benchmark: nie znaleziono polecenia
sms_ntsc_benchmark: níor aimsíodh an t-ordú
sms_ntsc_benchmark: no se encontró la orden
sms_ntsc_benchmark: no s'ha trobat l'ordre
sms_ntsc_benchmark: opdracht niet gevonden
sms_ntsc_benchmark: parancs nem található
sms_ntsc_benchmark: perintah tidak ditemukan
sms_ntsc_benchmark: príkaz nenájdený
sms_ntsc_benchmark: příkaz nenalezen
sms_ntsc_benchmark: команда не найдена
sms_ntsc_benchmark: командата не е открита
sms_ntsc_benchmark: 命令找不到
sms_ntsc_benchmark: コマンドが見つかりません